System for identifying authorized use of credit cards

ABSTRACT

A credit card system for providing verification of authority of a credit card bearer to use the credit card for a credit transaction. Initial authorization of card use is given to the authorized user upon selection by the user of one of a set of supplemental characters appearing on the card as the authorized user&#39;s private identifier. Presentation of the card at a point of sale initiates a check of this private identifier against a supplemental character identified by the presenter of the card as his/her private identifier.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for identifying a presenter ofa credit card for a credit transaction as an authorized user of thecredit card.

2. Description of the Prior Art

Credit cards have proved fertile ground for fraud and theft. Theinterest of the financial industry in maintaining a credit card systemwhich is both streamlined and easy to use is threatened by theoverriding interest of maintaining security. The ease with which thievesobtain all information necessary for fraudulent use of a credit carddirectly from the face of the credit card or from discarded invoices,portions of the credit slip, or carbon papers torn from credit slips hasrepeatedly compromised security.

A number of examples attempted solutions to the problem of credit cardfraud appear in the prior art. For example, U.S. Pat. No. 4,643,453issued to Shapiro et al. and entitled CREDIT CARD SECURITY SYSTEMSproposes the use of auxiliary character markings corresponding to monthsof the year for which the card is valid. The bank upon receipt of thebank copy of the invoice will accept the invoice for payment only if itcontains proper auxiliary markings for the date of use of the card.

U.S. Pat. No. 4,626,669 entitled INTERCEPT SYSTEM FOR INTERCEPTINGSTOLEN, LOST AND FRAUDULENT CARDS requires the card to have apermanently recorded electromagnetically readable tape laminated ontothe card body. The visibly readable portions of the card must matchnumbers derived from machine readable codes recorded on the magnetictape. The magnetic tape may also include a code to generate anidentification number which must be memorized by the cardholder andwhich does not appear on the face of the card.

Similarly, U.S. Pat. No. 4,105,156 issued to Dethloff and entitledIDENTIFICATION SYSTEM SAFE-GUARDED AGAINST MISUSE teaches the inclusionof an integrated circuit on an identification card for storing a secretnumber, which a user must remember to verify that he is the authorizeduser of the card.

Other patents, particularly U.S. Pat. No. 3,972,138 issued to Armbrusteret al. entitled CREDIT CARD; U.S. Pat. No. 3,713,235 issued to Robertset al. entitled COMBINATION CREDIT CARD; U.S. Pat. No. 3,624,938 issuedto Richard entitled FOOLPROOF CREDIT CARD; and U.S. Pat. No. 3,399,473issued to Jaffe entitled COMBINATION CREDIT CARD disclose a variety ofmechanical adaptions of credit cards whereby a user may indicate hispersonal secret code or authorization.

Additionally, simplification for use and improved reliability of remoteterminals for central data processing systems have provided a backdropfor verification of authority to cash checks as taught in suchdisclosures as U.S. Pat. No. 4,187,498 issued to Creekmore.

However, employment of such improved communications to provide anauthorized user of a credit card with both quick verification of his/herauthority has not been provided. Such a system would additionally allowthe authorized user to quickly change indicia of his/her authority. Akey to such an improvement is provided by allowing the cardholder asecret identifier as his/her authority and by providing for his/herchanging that symbol to maintain its secrecy.

SUMMARY OF THE INVENTION

The present invention employs no conceptual elements which are notalready a part of the credit card system. Accordingly, the securitysystem of the present invention employs credit cards, but modified inaccordance with the invention, conventional credit card purchaseinvoices or charge slips and a modified account data file for eachissued credit card.

The modified credit card of the present invention is issued to apotentialy authorized user. However, before use of the card, thepotential user must provide the credit card issuer with a letter orcharacter for inclusion in his account data file. The selected letter orcharacter will remain in the file and must be provided by the user uponpresentation of the card for use in a credit transaction.

The authorized user of the card will select the letter or character froma set of supplemental characters which are embossed into the card. Onecharacter will be provided corresponding to each digit of the accountnumber appearing on the card. The supplemental characters will bedisposed on the cards in such a way as to indicate each character'scorresponding digit in the account number.

When the credit card is presented to a merchant for use in a purchase,the merchant will request that the presenter identify a character fromthe supplemental set to conform the presenter's authority to use thecard. One way of doing this will be for the merchant to process the cardinvoice using the credit card to imprint both the account number and thesupplemental set of characters onto the invoice. The cardholder willthen circle or indicate his/her selected letter or character on his/herreceipt copy of the invoice set. The merchant then may relay the accountnumber and the selected code character to the card issuer. The cardissuer will check to see that the information provided corresponds tothe information in its official record. Where it does, the card issuermay authorize use of the card for the transaction.

A cardholder may change the selected code at any time by calling thecard issuer and identifying selected information in his account filesuch as his/her name, address and social security number which areretained in the account data file.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a credit card modified in accordance with oneembodiment of the present invention:

FIGS. 2A and 2B are views of conventional credit slips used in thesystem of the present invention;

FIG. 3 is a plan view of the customer copy of the credit slip of FIG. 2marked by a presenter of a credit card to verify his/her authority touse the card;

FIGS. 4 and 4A schematically depict information flows between elementsof the present invention and indicate information retained in data fileswith respect to each account file in the system;

FIG. 5 is a plan view of a back of a credit card showing a magneticstrip and a slip arrangement provided in the system of the presentinvention to modify read-out characteristics of the magnetic slip toindicate the presenter's indication of his/her secret code.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a credit card 10 which has a front face 11. A firstset of numeric characters 12 is embossed on the front face 11 indicatingan account number. Embossed as raised characters in one to onecorrespondence with the characters of the account number 12 is a secondset of supplemental characters 14. Second set of supplemental characters14 typically comprise the letters of the alphabet without the letters Ior O. Each character of the supplemental set 14 is otherwise randomlyselected from the English alphabet. A third set of embosed raisedcharacters 16 indicates the cardholder's name, and a fourth set ofembossed characters 18 indicates the expiration date of the credit card.

FIG. 2A illustrates a conventional credit slip or invoice 20, comprisinga merchant copy 22, a customer copy 24, and a bank copy 26. Credit slip20 has been processed by a clerk of a merchant. Accordingly, animpression 32 of account number 12, an impression 34 of supplementalcharacter set 34; an impression 36 of name set 16; and an impression 38of the expiration date 18 appear on the merchant copy, customer copy andbank copy of credit slip 20. Credit slip 20 has been marked by the clerkto indicate an item purchased and a total amount.

FIG. 2B illustrates an exploded view of credit slip showing that creditslip 20 is a layered set of sheets including merchant copy 22, acustomer copy 24 and bank copy 26, which are interleaved with carbonpapers 23 and 25.

FIG. 3 illustrates customer copy 24 of credit slip 20 which has beenmarked by its presenter to indicate a .[.characater.]. .Iadd.character.Iaddend.in supplemental set 34. A clerk processing the transaction maythen relay to the card issuer the code 3L, that is, the supplementalcharacter indicated by the card presenter and its corresponding digit inaccount number 32.

FIG. 5 illustrates a modification of the system where electronicterminals are used to read and automatically relay information to thecard issuer central data processing unit. Credit card 10 comprises aback face 13 on which a magnetic tape 40 is fixed. Magnetic tape 40includes a code representing the account number as well as otherinformation. A slip 42 is provided which fits snugly around card 10 andon which is disposed a magnetically non-conductive region 44 whichblocks reading a portion of magnetic strip 40. Slip 42 may be disposedon card 10 such that region 44 blocks a portion of magnetic tape 40corresponding to the digit of the account number corresponding with thecharacter from the supplemental code. This is done by aligning arrow 46with the selected character from supplemental character set 48, or ifarrow 46 is disposed on the opposite leaf of slip 42, by aligning arrow46 with the selected characters from set 14. Upon reading the code, thecentral data processing unit may resolve the authorized user's selectedcode letter.

FIG. 4 illustrates the information flows of the system of the presentinvention System 100 comprises a central data processing and filemaintenance unit 50, a plurality of merchants terminals 58, and aprivate communcations link 54 between the central processing unit 50 andan authorized card user. Private communication link 54 may be atelephone link between an authorized user and the central dataprocessing unit 50, or an employee of the card issuer with access to thecentral processing unit 50. Alternatively, private communication link 54may be the mails, private messenger service or personal appearance by auser or potential authorized user at the offices of card issuer.

Terminals 58 are present in all merchant establishments which acceptcredit cards from the card issuer for credit transactions. A terminal 58may be a telephone link between a clerk of the merchant and an employeeof the card issuer, the merchant identifying itself by a merchant codenumber. Alternatively, terminal 58 may be a data reception andtransmission terminal adapted to read information from the cardholder'scard and to accept input of the secret identification code. Such aterminal 58 also will be in communication directly with the central dataprocessing unit 50 by a telephone link.

FIG. 4A illustrates information maintained in an account data file inthe central data processing unit 50. Such a file 60 will include theauthorized card user's name, his/her social security number, an accountnumber corresponding to the account number appearing on the credit card,a secret ID code corresponding with the supplemental character selectedby the card user and its corresponding digit from the account number,the supplemental character set appearing on the card, the cardholder'saddress and an account history.

Operation of the system will now be discussed with reference to all ofthe figures herein. An initial application for issuance of a credit card10 is made by a potential authorized user over private communicationslink 54. At such time the card issuer will request initializingidentification data from an account data file 60. Such information mayinclude, for example, the potential user's name, his/her social securitynumber and his/her address, as well as other more obscure information(such as mother's maiden name) which can be used to verify the user'sidentify. After receipt of such data, the card issuer will issue acredit card 10 to the potential user over private communication link 54.At such time an account number 12 is supplied along with a set ofsupplemental characters 14. Before the card issuer authorizes the use ofcredit card 10, it will request and receive only private communicationlines 54 the card user's selection of a character from supplementalcharacter set 14. This information will be retained in account data file60 for later use in verifying a card presenter's authority to use creditcard 10. Alternatively, a supplemental character may be assigned to theuser upon issuance of the card and authority to use the card grantedupon issuance.

Presentation of credit card 10 at a merchant is only slightly differentthan prior modes of presentation. The bearer of credit card 10 presentscredit card 10 to a merchant in conjunction with the purchase of goodsor services The merchant will process a conventional credit slip orinvoice 20 by impressing representations of the embossed portions ofcredit card 20 onto credit slip 20 and entering a dollar and centsamount of the purchase in the appropriate spaces provided on credit slip20. The merchant may then present customer copy 24 of credit slip 20 tothe card bearer whereupon the card bearer will indicate on customer copy24 a character selected from supplemental character set 14 imprintedonto customer copy 24. Written notation of the supplemental characterprevents a non-authorized party from overheating the selected character.The merchant will then transmit over terminal 58 the account number andthe selected character to central processing 50 for verification.Central data processing will examine data file 60 for the appropriateaccount to determine whether the supplemental character transmitted fromterminal 58 matches the character stored in account file 60. Only ifthey match will central data processing approve the transaction.

Alternative modes of supply the clerk a selected character may be useddepending on the environment or the desirability of not marking evencustomer copy 24.

As indicated above, if terminal 58 is provided with means forelectromagnetically reading the magnetic strip on credit card 10,communication of the selected character may be done without marking ofcustomer slip 24.

Private communications link 54 may be used by an authorized user tochange his/her selected supplemental character. An authorized userinitiates communication with central data processing over privatecommunication link 54 and indicated his/her desire to change his/herselected code. Central data processing 50 then requests the useridentify data in account data file such as his/her name, social securitynumber, and address. Upon successful identification of such privatepersonal information, central data processing allows the authorized userto change his/her selected code and will store the current selected codein account data file 60. Accordingly, an authorized user may changehis/her selected code, for example, after every use of credit card 10.

The present invention provides for streamlined, quick and yet highlyprivate method for verifying authority of a card presenter for use ofthat card. Private communication links also offer a convenient means forthe diligent card user to protect himself/herself and the secrecy ofhis/her personal code from the use of unauthorized individuals.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. A system for indicating a bearer of a credit cardas its authorized cardholder, the system comprising:a plurality ofcredit cards issued to cardholders, each credit card .[.being embossedwith.]. having a first set of .[.raised.]. characters indicating anaccount number and .Iadd.having .Iaddend.a supplemental set of.[.raised.]. characters which have a one to one correspondence with each.[.digit.]. .Iadd.character .Iaddend.of the account number; an accountdata file for each account number comprising identification data withrespect to a cardholder, the identification data being also known ordeterminable by the cardholder, the account number, a cardholderidentification code comprising the account number, a character selectedby the cardholder from the set of supplemental characters and the.[.digit.]. .Iadd.character .Iaddend.in the account number correspondingto the selected character; and means for matching the account numberappearing on a presented credit card with its respective account datafile and for comparing a supplemental character identified from thepresented credit card by the bearer with the selected supplementalcharacter appearing in the cardholder identification code; whereby amatch indicates the bearer as being the cardholder and lack of a matchindicates the bearer is not the cardholder.
 2. The system as defined inclaim 1, wherein the matching and comparing means further comprises:dataprocessing means for maintaining the plurality of account data files,for calling account data files in response to input of cardholderaccount numbers, for determining matches between a supplementalcharacter identified by the presenter with the selected supplementalcharacter, and for generating approval or disapproval indications as aresult thereof; a data terminal at the point of presentation of a creditcard for relaying credit card generated and presenter generated data tothe data processing means and for displaying approval or disapprovalindications; and a communications link between the data terminal and thedata processing means.
 3. The system as defined in claim 2, wherein thecredit card comprises:.[.raised.]. characters indicating a name of thecardholder; .[.raised.]. characters indicating the expiration date ofthe card; and a machine-readable representation of the cardholderaccount number.
 4. The system as defined in claim 3, wherein the dataterminal further comprises means for reading and transmitting themachine-readable representation of the cardholder account number.
 5. Thesystem as defined in claim 4, further comprising sleeve means adapted tobe fitted over the credit card to alter the machine readout of itsrespective account number to indicate the .[.digit.]. .Iadd.character.Iaddend.corresponding to a supplemental character identified by thepresenter.
 6. The system as defined in claim 2, the system furthercomprising:means for changing the selected supplemental character in theaccount data file at the behest of the cardholder upon identification bythe cardholder of selected data in the account data file.
 7. The systemas defined in claim 1, wherein the set of supplemental characters isselected at random from a set of characters.
 8. The system as defined inclaim 1, further comprising:a charge slip having a plurality of sheetswhich can be marked by the .[.raised.]. characters of a credit card, anyone of which sheets can be separately marked upon by the credit cardbearer to identify a supplemental character.
 9. A method of verifying abearer of a credit card as its authorized user, the method comprisingthe steps of:issuing a credit card to an authorized user, .[.embossedwith.]. .Iadd.having .Iaddend.a first set of .[.raised.]. charactersindicating an account number and a second set of .[.raised.].supplemental characters, each of the supplemental characters being inone to one correspondence with a particular .[.digit.]. .Iadd.character.Iaddend.of the account number; requiring the authorized user to selectat least a first supplemental character from the second set of.[.raised.]. characters before the allowing the credit card to be usedfor credit transactions; retaining in an account data file for eachissued credit card, identification data with respect to the authorizeduser, the account number and a user identification number formed fromthe account number, the selected supplemental character and thecorresponding .[.digit.]. .Iadd.character .Iaddend.supplementalcharacter from the account number; employing the credit card to printthe account number and the supplemental characters .[.or.]. .Iadd.on.Iaddend.a charge slip including at least a customer copy of the chargeslip; matching the account number appearing upon the credit card withits respective account number file upon presentation of the credit cardfor use; having the bearer of the presented card .[.mark.]..Iadd.indicate .Iaddend.a supplemental character .[.on the customer copyof the charge slip.]. comparing the .[.marked.]. .Iadd.indicated.Iaddend.supplemental character to the selected supplemental characterin the account data file; and approving the transaction if and only ifthe indicated supplemental character matches the identified supplementalcharacter.
 10. A credit card system which comprises:a credit card with apair of primarily flat faces; a first set of .[.raised.]..Iadd.characters .Iaddend.on the first face of the credit cardindicating an account identification code; a machine-readablerepresentation of the characters of the account identification code; asupplemental set of .[.raised.]. characters on the credit card, eachcharacter of the supplemental set having a correspondence to a differentfirst set character; and a sleeve fitted over the credit card to alterthe machine-readable representation of the cardholder account code uponalignment of the sleeve with a character from supplemental set characteridentified by a bearer of the credit card.